The show, shown at prime time viewing slots, was a wish-fulfillment vehicle, where children would write in asking Jim to fix it for them to do something (anything!) they'd always wanted to do. Jim would pick a few winners every week and read out their letters (always beginning with the immortal lines "Dear Jim, Could you fix it for me to...") before wheeling out said kiddie in front of the cameras and running a film of their dream coming true.

Examples of the kind of things he 'fixed' for lucky children were;Launching new ocean liners, demolishing factory chimney stacks, racing in Formula One cars, singing with The Nolan Sisters, etc.